Fabrication of electrochemically-modified BiVO-MoS-CoOcomposite film for bisphenol A degradation.

A new electrochemically-modified BiVO-MoS-CoO (represented as E-BiVO-MoS-CoO) thin film electrode was successfully synthesized for environmental application. MoS and CoO were grown on the surface of BiVO to obtain BiVO-MoS-CoO. E-BiVO-MoS-CoO film was achieved by further electrochemical treatment of BiVO-MoS-CoO. The as-prepared E-BiVO-MoS-CoO exhibited significantly enhanced photoelectrocatalytic activity. The photocurrent density of E-BiVO-MoS-CoO thin film is 6.6 times that of BiVO under visible light irradiation. The degradation efficiency of E-BiVO-MoS-CoO for bisphenol A pollutant was 81.56% in photoelectrochemical process. The pseudo-first order reaction rate constant of E-BiVO-MoS-CoO film is 3.22 times higher than that of BiVO. And its reaction rate constant in photoelectrocatalytic process is 14.5 times or 2 times that in photocatalytic or electrocatalytic process, respectively. The improved performance of E-BiVO-MoS-CoO was attributed to the synergetic effects of the reduction of interfacial charge transfer resistance, the formation of oxygen vacancies and sub-stoichiometric metal oxides and higher separation efficiency of photogenerated electron-hole pairs. E-BiVO-MoS-CoO is a promising composite material for pollutants removal.